That's not even a little bit true. Lomachenko gets WAY more credit from fans, and specifically Boxing media for beating Rigondeaux compared to Mayweather beating Marquez. When have you heard a Mayweather fan (who you believe knows boxing) or boxing media defend his legacy by bringing up the Marquez win? I ask, because if you posted that tweet without further explanation, I'm going to assume you agree with it.
Lomachenko beats Rigondeaux and people are making comparisons to Mayweather, Chavez, Duran etc.There's even a thread right now comparing Lomachenko to Mayweather. Mayweather beat Marquez and I don't recall anyone saying that win makes them believe he can beat Ray Robinson, Leonard, Hearns etc. Nobody on any boxing forum and no boxing journalist ever made a thread or article after the Mayweather vs Marquez fight saying, "Hmmm, Based on Mayweather's performance against Marquez, I think he can beat Sugar Ray now?" It just didn't happen.
Whether Mayweather is "TBE" or whatever is a matter of opinion, and a debate I'd rather not touch. However, I have ears, and have never heard boxing experts bring up the Marquez fight as Mayweather's #1 win when talking about his greatness.